Boiler feeder



Dec. 12, 1939. D. JORDAN ET AL BOILER FEEDER Filed Sept. 4, 1957 2 Sheets-Sheet l WZ Zw fl 5 5 H D5 [Q E s J Patented Dec. 12, 1939 UNITED STATES BOILER FEEDER James D. Jordan, Oak Park, and Daniel F. Ellis and Cecil W. Preston, Chicago, Ill., assignors to General Household Utilities Company, Chicago, 111., a corporation of Delaware Application September4, 1937, Serial No. 162,563

12 Claims.

The present invention relates in general to the delivery of fluid into a chamber or container under relatively high pressure from a source or reservoir at lower pressure, and the invention has more particular reference to boiler feed apparatus, and while the invention is especially adapted for the delivery of liquid in the boiler of refrigerating apparatus of the character illustrated and described in the co-pending application of William C. Grunow et al. for United States Letters Patent, Serial No. 144,346, filed May 24, 1937, the present invention is not necessarily restricted to use in conjunction with refrigerating apparatus, but may have general application.

An important object of the invention is to provide simplified means for feeding liquid into a container, such as a boiler, from a supply source which is at a relatively lower pressure, the invention relating more particularly to the provision of simplified means having a minimum number of moving parts whereby the same does not readily get out of order in service.

Another important object is to provide a boiler feed device operable in conjunction with the condenser of a refrigerating system and a boiler providing vapor under pressure for the actuation of jet pumps for causing circulation of a refrigerant in the refrigerating system in order to deliver liquid from the condenser into the boiler against the relatively high pressure maintained therein during the operation of the system.

Another object is to accomplish the delivery of a boiler feed medium by instantaneously evaporating a predetermined quantity of the medium at intervals to generate pressure in excess of that prevailing in the boiler and utilizing such generated pressure to force the remainder of the'.

boiler feed medium into the boiler.

Another important object is to provide boiler feed means comprising a chamber having valved connection with the boiler and with a low pressure source of supply whereby the boiler feed medium may be delivered into said chamber from said source at a predetermined rate through a check valve, including means operable after a predetermined quantity of the medium has thus been introduced into the chamber, to cause sudden evaporation of a portion of the medium to generate in said chamber a pressure suflicient to force the rest of the medium from the chamber through a check valve and into the boiler.

Another important object is to provide a vaporizing chamber, the walls of which are of substantial mass, having an appreciable heat storage capacity, including means to continuously heat the walls and maintain the same at a temperature such that upon delivery of a predetermined quantity of the boiler feed medium into the vaporizing chamber the mediumso delivered will be quickly vaporized; a further object being to connect the vaporizing chamber with a liquid delivery chamber adapted to receive substantial quantities of the feed medium from a source of supply whereby upon vaporization of the predetermined quantity, the pressure derived therefrom will force the liquid from the receiving chamber into the boiler.

Another important object is to provide a measuring bucket adapted to be filled witha predetermined quantity of the boiler feed medium after the storage chamber has filled with feed medium to a predetermined level, the bucket after receiving said predetermined quantity being arranged to dump the same rapidly into the vaporizing chamber.

A further object is to utilize the measuring bucket to control a check valve through which the receiving chamber has communication with the low pressure source of the boiler feed medium so that said check valve may be released for closure as the bucket dumps its charge into the vaporizing chamber to the end that the pressure developed for the purpose of forcing the feed medium into the boiler may not be dissipated to said source.

Numerous other objects, advantages and inherent functions of the invention will, become apparent as the same is understood from the following description which, taken in'connection with the accompanying drawings, discloses a preferred embodiment of the invention.

Referring to the drawings, Fig. 1 is a diagrammatic showing of a refrigerating system of the character illustrated and described in the aforesaid application of William C. Grunow for United States Letters Patent and containing boiler feeding means embodying the present invention;

Fig. 2 is a sectional, somewhat diagrammatic view of a boiler feeding device embodying the present invention;

Fig. 3 is a perspective view of the boiler and boiler feeding device shown in Fig. 1;

Fig. 4 is a sectional view taken substantially along the line 4-4 in Fig. 3, to illustrate the internal construction of the boiler;

-"Fig. 5 is a, sectional view taken substantially along the line 5-5 in Fig. 3, in order to show the internal arrangement of the boiler feed device: and

Fig. 6 is a perspective view of a measurin bucket forming a part of the boiler feed device.

To illustrate our invention we show on the drawings a feeding device ii for delivering a fluid into a container l3, such as a boiler, at relatively high pressure from a source of supply H3 at relatively lower pressure, and while the invention may have general application, particularly in feeding liquid to boilers, we have shown the device ll connected in a refrigerating system of the character illustrated in the application of William C. Grunow for United States Letters Patent, Serial No. 144,346, filed May 24, 1937, the same comprising a refrigerating system adapted for operation on the compression-condensationevaporation cycle. wherein a refrigerating medium, in gaseous condition, is compressed by the pumping means I! and delivered to a condenser 20, and wherein the refrigerating medium is cooled to liquefy the same at substantially compression pressure. The liquefied medium may then be delivered through suitable pressure controlling equipment, such as a float valve 2| to a relatively low pressure heat absorbing zone shown in the illustrated embodiment as an evaporator 23, in which the liquid refrigerant is permitted to evaporate in order to absorb heat, the resulting vapors produced in evaporators 23 being returned to the suction or low pressure side of the refrigerant compressing means I1, preferably through a check valve 25.

The pumping means comprises jet pumps l8 which are actuated by vapor under pressure preferably derived by the application of heat to a suitable medium, which medium may comprise a portion of the refrigerating medium itself. The operation of a refrigerating system by means of jet pumps, as demonstrated in the aforesaid application of William C. Grunow et al. for United States Letters Patent, is feasible providing the refrigerating medium has vapor pressure characteristics such that under normal temperature conditions the refrigerant may be evaporated and condensed within certain pressure differentials commercially maintainable. Such a medium is trichloro-trifiuoro-ethane C2F3Cl3, commonly known as Carrene No. 3.

In a system of the character described, a portion of the condensed refrigerant may be drawn from the condenser and delivered in the boiler l3 and there evaporated to produce vapor under pressure for the actuation of the jet pumps, the liquid delivered in the boiler 13 being there evaporated by the application of heat in any suitable or convenient manner, as by the burning of fuel under the boiler l3, the same being illustrated as a gas burner 27. If desired, the vapor may be thoroughly dried and slightly superheated by passing the same through the coil 29 before delivering it to the jet pumps IS.

The system, of course, may be operated by utilizing a pump actuating medium in the refrigerating medium, providing some means is provided for separating the pump actuating from the refrigerating medium after the same are liquefied in the condenser. Furthermore, it should be clearly understood that the present invention is not necessarily restricted to a boiler feed device for use in refrigerating systems of the character mentioned. At the same time the feeding device of the present invention is particularly well suited for delivering liquid from the condenser, which is at relatively low pressure compared with presaieawi sure maintained in the boiler l3, into the boiler. although it will be apparent that the feeding device may be used to deliver any kind of boiler feeding liquid to the boiler.

The invention may have application in connection with the boiler of any suitable or preferred construction. As shown for purposes of illustration the boiler comprises a shell having fire tubes 3i heated in any manner, as for example, electrically or by the combustion of gas, oil or any other fuel, the heating device or burner being located as shown at the lower end of the boiler, and the products of combustion, after passing through the tubes 3i, are conducted through a fiue 33 of suitable construction, in which flue the superheating coil 29 may be arranged.

To deliver liquid from the supply source l5 into the boiler IS, the device II is arranged with a chamber 31 adapted to receive liquid from the source through a pipe or conduit 39 with which is associated a valve 41, permitting only one-way liquid flow from the source to the chamber. The device II also has a vaporizer 43 adapted, at intervals, to evaporate a predetermined quantity of liquid and thus develop pressure, at least equal to that prevailing in the boiler I3 in order to permit the liquid to enter the boiler and thus feed the same. To this end the chamber 37 is connected to the boiler by means of a pipe or conduit 45, which has a valve 4| permitting only one way liquid flow from the chamber 31 to the boiler.

The vaporizer 43 is connected, preferably, to the top of the chamber 31, as at 49, said connection affording an overflow for liquid from the chamber into the vaporizer after a predetermined quantity or charge of liquid has entered the chamber 3! from the source. The vaporizer is preferably formed as a thick walled element having an appreciable heat storing capacity and the same is continuously heated, either separately as shown in Fig. 2, or by the same source of heat used to heat the boiler [3. As shown in Fig. 1, the vaporizer is a thick walled casting, preferably of metal, having a plurality of fire tubes like the tubes 3| of the boiler. The walls of the vaporizer define a liquid space around the fire tubes and the device may be arranged immediately beneath the boiler with its fire tubes in line with those of the boiler so that the vaporizer is at all times exposed to the hottest parts of the burner El.

As soon as liquid is delivered into the hot vaporizer, it will evaporate and generate pressure which, through the connection 49, is made available to equalize the pressure of the chamber 37 with that of the boiler 13, or develop excess pressure in the chamber, thereby causing the liquid to flow from the chamber through the check valve ll, into the boiler. The check valve 41, during this boiler feeding period, of course, prevents the pressure from dissipating to the low pressure source. l

Incidentally, the heat applied in vaporizing the liquid in the vaporizer 43 is transferred to the boiler feed liquid in the chamber 3'! which is thus preheated appreciably as it is forced to the boiler. Thus the heat energy applied to the vaporizer is not entirely lost.

The quantity of liquid required to be charged into the vaporizer in order to develop enough vapor to completely displace all of the liquid from the chamber 3'! depends upon the character of the liquid and the amount to be fed into the boiler. The exact quantity required can be easily computed for any desired application, but it is preferable, of course, that the entire amount of liquid be fed into the vaporizer all at substantially the same instant to permit instantaneous development of all of the vapor needed to displace the liquid in the chamber 31. We therefore have provided a measuring bucket positioned to receive overflow liquid, delivered from the chamber 31, until the bucket has received a predetermined quantity or charge, at which instant the bucket is designed to dump its contents into the vaporizer 43. The bucket is of a character adapted, when empty, to hang upright against a stop 53, the center of gravity of the empty bucket being below and at one side (the left side in Fig. 5) of the tilting axis of the bucket. The bucket, however, is designed so that, as it is filled with liquid, the center of gravity of bucket and contents shifts to a point above and to the opposite side (the right side in Fig. 5) of the tilting axis, thereby causing the bucket to tilt and discharge its contents after receiving a predetermined quantity of liquid. The bucket is arranged also, to remain in tilted or liquid discharging position, after being initially overbalanced, until all of its contents have discharged, at which time the weight distribution of the material of the bucket causes it to regain its normal position.

After the liquid has been delivered into the boiler by operation of the vaporizer, the vapor remaining in the chamber eventually condenses since the walls of the chamber 31 are at,a temperature substantially below the boiling point of the feed medium. Upon condensation reduced pressure conditions are established in the chamber 31, thus permitting the valve 41 to open and liquid to be introduced into the chamber from the source. As soon as low pressure conditions are thus established in the chamber, the check valve 4| is, of course, closed by the higher pressure prevailing in the boiler, thereby preventing backflow from the boiler to the chamber 31 of the feeding device.

In order to accelerate the condensation of residual vapor in the chamber 31, after the delivery of liquid into the boiler, pressure relief means may be provided for establishing communication between the chamber 31 and the source |5 at a point above the level of the liquid therein while the pressure in the chamber 31 is in excess of that at the source l5. Theinterior of the chamber being exposed to the source, condensation takes place instantaneously and the device is conditioned to receive liquid from the source without undue delay. To this end a relief valve 1 may be connected with pressure responsive means adapted to-open the same when pressure in the chamber falls below a predetermined value. As shown in Fig. 5, the valve 1 comprises an element pivoted as at 55 to swing toward and away from a seat 51 connected with a conduit |9 which leads to the upper portion of the condenser 20. The valve may be provided with a finger 59 in position to engage a rack 6| operatively connected with pressure responsive means 63 adapted to shift the rack ,in a direction to open the valve when pressure within the chamber 31 falls below a predetermined value. In the embodiment shown in Fig. 5, the pressure responsive means 63 comprises a bellows, the outer endof which is anchored in and sealed to the walls of the chamber with the interior of the bellows exposed to atmosphere, while the other end of the bellows is sealed upon the disk-like head 69 of a stem 61 to which is pivoted the rack, as at 65.

As a matter of manufacturing convenience and simplicity of design, we prefer to form the device as a plurality of separate parts, including a preferably cylindrical casting forming the chamber 31; a generally cylindrical casting 13 forming a part of the vaporizer and comprising a housing for the bucket 5|, preferably separate from but connecting with the heated portions of the vaporizer 43, as by the pipe 15; a preferably cylindrical casting 11 forming a housing for the valve 1 and its actuating mechanism, said housing connecting with the chamber 31; and a manifold plate 19.

The bottom of the chamber 31 conveniently may be closed by means of a plug 1|, by means of which the conduits 39 and 45 may be connected with the chamber and in which plug, if desired,

the valves 4| and 41 may be arranged. The upper end of the chamber may be connected to the manifold plate 19 which is or may be formed with a bore 3|, connected with the chamber 31, and a cavity 83 communicating with the bucket housing 13. The bore 8| and cavity 83 are connected by channels forming the connection 49, there being preferably an upper large channel I49 to permit free passage of vaporized medium to the chamber 31, and a lower relatively smaller channel 249 to permit liquid to overflow from the chamber 31 and enter the bucket 5|. The plate 19 may be drilled as at 85 to permit formation of the channels I49 and 249 by drilling and the opening then closed by the plug 81.

The plate 19 may be secured, as by bolting or otherwise, upon the castings 31 and 13, and a cover 89 may be provided on the plate to close the upper end of the bore 8| and the chamber 31. The cover 89 may comprise the bottom of the valve housing 11 which, if desired, may be secured directly to the plate 19 with the housing 11 in direct communication with the chamber 31. We prefer to use a short pipe 9| to connect the housings. I

The valve housing 11, in the form shown, has a bottom in which one end of the pipe 9| is secured, and the top is closed by a removable cover. The valve seat 51 may be formed, conveniently, in a fitting adapted to be threaded in an opening in the side walls of the housing 11, the conduit 9 being fastened to the outer end of the fitting. The bellows 63 may be mounted on a plate 93 which is clamped, by a holding plate 95, in a lateral opening in the walls of the housing 11. The holding plate may be formed with openings 91 to expose the bellows to atmosphere and may carry an adjusting screw 99 accessible from without the housing to vary the tension on a spring ||l| which bears at one end upon a shoulder I03 on the stem of the screw. The spring extends through an opening in the plate 93 and bears against the head 69 of the valve opening linkage in order to aid atmospheric pressure in opening the valve 1. The plate also holds in place a collar I05 which serves to limit the movement of the head 69 under the influence of the spring and atmosphere. The screw 99 may Have a projection |01 extending within the spring |ll| to support the same against lateral buckling when in compression and also to limit travel of thebellows to prevent crushing.

The collar I05 may carry spring means I99 to urge the rack 6| toward the detent 59, and it will be seen that the spring |9| may be adjusted by the screw 99 to urge the valve 1 open and thus permit the same to open when the pressure in the chamber 31 (which is also the pressure in the housing 11) falls to a predetermined value,

which, of course, may be substantially in excess of atmospheric pressure.

As liquid from the source 15 enters and fills the housing 37 and, after reaching the overflow conduit 249, fills the bucket5l, it is desirable, if not necessary, to release the valve ll'l so that it may close immediately upon the dumping of the bucket 5| and consequent generation of boiler feeding vapor pressure in the chamber 37. To ensure that the valve will be free to close, the bucket is suspended in a bracket H which, in turn, is hung on one end of a lever H I in the cavity 83. The lever Ill may be fulcrumed, as at H3, in the channel M9; and has its other end extending in the bore BI and connected with the rack 6| by means of a connecting rod H which may extend from the end of the lever arm in the cavity 8|, through the pipe 9|, into the housing 71. The spring I09 is adapted to hold the rack down when the bucket 5| is empty and while it is filling. Just before dumping, the weight of liquid in the bucket, however, is sufiicient to tilt the lever Hi and raise the rack 61 from the detent 59, thus releasing the valve H7. The valve is so weighted that it will move toward closed position by gravity and closely overlie the seat 5'! so that'when the bucket discharges its load into the vaporizer the valve ll'l may be snapped tightly shut immediately upon the vaporization of the dumped liquid.

The liquid feeding device of our present invention may, of course, be applied to the delivery of any kind of medium required to be transferred from a supply source to a delivery station at relatively higher pressure and the invention consequently is not necessarily restricted to the delivery of liquid in a boiler from a condenser, nor to the feeding of boiler feed medium from a condenser forming a part of a refrigeration system of the character mentioned. The device of the present invention, however, is particularly well adapted for use in feeding an evaporable medium to a boiler used in generating vapor for the operation of jet pump compressors in a compression-expansion-evaporation refrigerating system.

The feeding device of the present invention has the advantages of compactness, efficiency and silence in operation, and affords an efficient means for delivering a liquid to a boiler. The invention, of course, has general application, although it is particularly well adapted for use in connection with refrigerating systems of the character heretofore mentioned, and when so applied makes feasible the provision of a commercially satisfactory refrigeration system of the compresslon-expansion-condensation type for operation by gas or other fuel.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing .description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts without departing from the spirit and scope of the invention or sacrificing its attendant advantages, the forms herein disclosed being preferred embodiments for the purposes of illustrating the invention.

What we claim as new and desire to secure by Letters Patent of the United States is as follows:

1. The method of delivering an evaporable medium to a boiler serving the jet compressors in a compressor-condenser-expander refrigerating system, which consists in Withdrawing refrigerant from the condenser of the system to an intermediate zone, heating a portion of the withdrawn refrigerant to develop vapor under pressure in excess of that in the boiler, and using the vapor thus produced to deliver the remainder of the withdrawn refrigerant into the boiler and alternately of said delivery step reducing the pressure to permit supplying of refrigerant to said intermediate zone from the low pressure supply by establishing vapor connection of the intermediate zone with the said low pressure supply.

2. The method of operating a compressorcondenser-expander refrigerating system employing jet compressors actuated by a boiler to circulate the refrigerant in the system which comprises withdrawing liquid refrigerant from the condenser of the system to an intermediate zone, heating a portion of the refrigerant thus withdrawn to develop vapor under pressure in excess of that which prevails in the boiler using the vapor pressure thus produced to deliver the remainder of the withdrawn liquid into the boiler, heating the liquid in the boiler to produce vapor under pressure, and returning the same to the condenser of the system through the jet pumps whereby to exert a pressure differential in remote portions of the system and thus cause the same to operate and alternately of said delivery step reducing the pressure to permit supplying of refrigerant to said intermediate zone from the low pressure supply by establishing vapor connection of the intermediate zone with the said low pressure supply.

3. The method, as set forth in claim 1, wherein the said heated portion of the withdrawn refrigerant is at least partially transferred to the remaining portions of the liquid and serves to preheat the same prior to the introduction thereof into the boiler.

4. A fluid feed device comprising receiving means to receive a fluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said receiving means whereby to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, including a check valve between the receiving means and the source and between the delivery zone and the receiving means, valve operating means, operable in response to decrease in pressure in the receiving means after expulsion of medium to the delivery zone, and a valve arranged between the supply source and the receiving means for controlling communication between said supply source and receiving means, said valve and valve operating means being operatively associated to open said valve when the operatingmeans is operated for equalizing the pressure in the supply source and the receiving means.

5. A fluid feed device comprising receiving means to receive a fluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said receiving means whereby to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, including a check valve between the receiving means and the source and between the delivery zone and the receiving means, valve operating means, operable in response to decrease in pressure in the receiving means after expulsion of medium to the delivery zone, and a valve arranged between the supply source and the receiving means for controlling communication between said supply source and receiving means, said valve and valve operating means being operatively associated to open said valve when the operating means is operated for equalizing the pressure in the supply source and the receiving means, including means to adjust the valve operating means to release the valve at a predetermined pressure.

6. A fluid feed device comprising receiving means to receive a fluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said receiving means whereby to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, including a check valve between the receiving means and the source and between the delivery zone and the receiving means, valve operating means, operable in response to decrease in pressure in the receiving means after expulsion of medium to the delivery zone, and a valve arranged between the supply source and the receiving means for controlling communication between said supply source and receiving means, said valve and valve operating means being operatively associated to open said valve when the operating means is operated for equalizing the pressure in the supply source and the receiving means, said valve operating means being operable in response to the differential in pressure within and Without the receiving means.

7, A fluid feed device comprising receiving means to receive a fluid medium from a relatively low pressure supply source, means to.

evaporate a part of the received medium and generate vapor pressure in said receiving means whereby to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, including a check valve between the receiving means and the source and between the delivery zone and the receiving means, valve operating means, operable in response to decrease in pressure in the receiving means after expulsion of medium to the delivery zone, and a valve arranged between the supply source and the receiving means for controlling communication between said supply source and receiving means, said valve and valve operating means being operatively associated to open said valve when the operating means is operated for equalizing the pressure in the supply source and the receiving means, said valve operating means being operable in response to the differential in pressurewithin and without the receiving means, and including adjustable spring means normally biasing said valve operating means toward valve opening position.

8. A fluid feed device comprising intermediate zone receiving means to receive a fluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said receiving means whereby to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, said evaporating means comprising a heated vaporizing chamber connected to the receiving means to receive and yaporize a quantity of medium after a prede- -termined amount of the medium has entered the receiving means from the source, and means operable in response to a drop in pressure in the receiving means to reduce, alternately of said delivery step, the pressure in the receiving means to permit supplying of refrigerant to said intermediate zone from the low pressure supply by establishing vapor connection between the intermediate zone and the low pressure supply.

9. A fluid feed device comprising intermediate zone receiving means to receive a fluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said receiving means whereby'to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, said evaporating means comprising a heated vaporizing chamber connected to the receiving means to receive and vaporize a quantity of medium after a predetermined amount of the medium has entered the receiving means from the source, means to deliver a measured quantity of the medium into said vaporizing chamber as an actuating charge, and means operable in response to a drop in pressure in the receiving means to reduce, alter nately of said delivery step, the pressure in the receiving means to permit supplying of refrigerant to said intermediate zone from the low pressure supply by establishing vapor connection between the intermediate zone and the low pressure supply.

10. A fluid feed device comprising intermediate zone receiving means to receive a. fluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said relivery zone in which the prevailing pressure is higher than that at the supply source, said evaporating means comprising a heated vaporizing chamber connected to the receiving means to receive and vaporize a quantity of medium after a predetermined amount of the medium has entered the receiving means from the source, a self-righting measuring bucket in position to receive a predetermined quantity of the medium as overflow from the receiving means and dump the same into the vaporizing chamber, and means operable in response to a drop in pressure in the receiving means to reduce, alternately of said delivery step, the pressure in the receiving means to permit supplying of refrigerant to said intermediate zone from the low pressure supply by establishing vapor connection between the intermediate zone and the low pressure supply.

11. A fluid feed device comprising receiving means to receive afluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said receiving means whereby to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, said actuating means comprising a heated vaporizing chamber connected to the receiving means to receive and vaporize a quantity of medium after a predetermined amount of the medium has entered the receiving means from the source, a check valve between the source and said receiving means and opening toward the latter to seal the same from the source when vapor pressure is developed in said receiving means, valve operating means operable in response to decreasing pressure in said of the medium, as a charging unit, into a dereceiving chamber after expulsion of medium therefrom to the delivery zone, a valve arranged between the supply source and the receiving means for controlling communication between said supply source and receiving means, said valve and valve operating means being operatively associated to open said valve when the operating means is operated for equalizing the pressure in the supply source and the receiving means, and means to deliver a quantity of the medium into the vaporizing chamber as an actuating charge, and in cooperation with said valve actuating means to release said valve for closure prior to the delivery of said actuating charge into said vaporizing chamber.

12. A fluid feed device comprising receiving means to receive a fluid medium from a relatively low pressure supply source, means to evaporate a part of the received medium and generate vapor pressure in said receiving means whereby to force the remainder of the medium, as a charging unit, into a delivery zone in which the prevailing pressure is higher than that at the supply source, said actuating means comprising a heated vaporizing chamber connected to the receiving means to receive and vaporize a. quantity of medium after a predetermined amount of the medium has entered the receiving means from the source, a check valve between the source and said receiving means and openlng toward the latter to seal the same from the source when vapor pressure is developed in said receiving means, valve operating means operable in response to decreasing pressure in said receiving chamber after expulsion of medium therefrom to the delivery zone, a valve arranged between the supply source and the receiving means for controlling communication between said supply source and receiving means, said valve and valve operating means being operatively associated to open said valve when the operating means is operated for equalizing the pressure in the supply source and the receiving means, and a self-dumping measuring bucket in position to receive a predetermined quantity of the medium as overflow from the receiving means and to dump the same into the vaporizing chamber as an actuating charge, said bucket being operatively connected with said valve operating means to release said valve for closure when the bucket contains a quantity of liquid just short of that required to dump the bucket.

JAMES D. JORDAN. DANIEL F. ELLIS. CECIL W. PRESTON. 

